Filter



June 16, 1953 c. s. GARLAND ETAL 2,642,186

FILTER- Filed Nov. 50, 1950 7 SheetsSheet 1 Inverfiors Chum Lam: 21M

A ttorn e y:

June 1953 c. s. GARLAND ETAL 2,642,186

' v FILTER Filed Nov. 30, 1950 7 Sheets-Sheet 2 j lnven lora L A ttbmey:

June 16, 1953 c. s. GARLAND ETAL 2,642,186

FILTER Filed Nov. 30, 1950 7 Sheets-Sheet 3 June 16, 1953 c. s. GARLANDEAL 2,

' FILTER Filed Nov. 50, 1950 7 Sheets-Sheet 4 llllIIIIIIIIIIMIIIIHHIIIF& au

1 la n Inventors By m $011..

Attorney C. S. GARLAND ET AL June 16, 1953 FILTER 7 Sheets-Sheet 6 FiledNOV. 30, 1950 Inventors A tiorney June 16, 1953 c. s. GARLAND E'I'ALFILTER 7 Sheets-Sheet 7 Filed Nov. 50, 1950 Inventors J 'ZMW y M; a MAttorney;

Patented June 16, 1953 FILTER Charles Samuel Garland and Francis HeronRogers, London, England Application November 30, 1950, Serial No.198,258 In Great Britain December 1, 1949 16, Claims. 1

This invention relates to filters of the kind in which a liquid isfiltered by passing it through passages,'of a predetermined size,between the adjacent surfaces of a plurality of filter elements formingthe filtering member which are assembled upon a hollow support ordrainage member through which the filtered liquid passes afterfiltration.

Filters of the kind above referred to have hitherto been manufactured intwo different ways. The first consists in forming the filter as anassembly of rings or discs arranged on a central drainage member andsecured together .by endwise compression, the rings or discs normallybeing minted so as to provide a predetermined space for edgewisefiltration between adjacent discs. Alternatively, the discs or rings areformed of surfaced paper or like material, the

' gap between the adjacent discs being determined capable of accurateadjustment, or practically so,

when in operation, their use for different degrees of filtrationnecessitating dismantling for adjustment or the interchange of filterelement assemblies.

A further difficulty which has arisen in the use of filters of the kindaforesaid has been that of cleaning the filter elements of the foreignmatter removed from the liquid during filtration, this difiiculty beinggreater when a fine degree of filtration was being carried out.

Some of the difficulties inherent in filters of the kind referred tohave been removed by the employment of carefully graded filter aid butin some kinds of filtration in which very fine filtration is requiredthe employment of filter aid is not suitable.

Although filters of the kind above referred to have hitherto beendesigned to give a predetermined space between adjacent filter elementsin order to determine the degree of filtration, it has not normally beenpossible to eifect any degree of positive and accurate adjustment of thegap between adjacent filter elements.

The invention aims at providing a filter of the kind above referred toin which the degree of filtration may be positively regulated, ifdesired during the operation of the filter, by adjustment of the gapsbetween adjacent filter elements, the adjustment beingsuch as to providean accurate variation in the degree of filtration from that provided bya micro-filter to that provided by a strainer.

The invention further aims at providing a means whereby the surfaces ofthe adjacent filter elements may be positively cleaned withoutdismantling the filter, in addition to the degree of cleaning which maybe effected by the normal operation of back-flushing the filter.

A further object .of the invention is the provision of a filter capableof separating admixed liquids, in which one liquid forms an emulsion ordispersion with the other, such as oil in a continuous phase and waterin a discontinuous phase.

According to the invention a filter of the kind above referred to isprovided wherein means are provided for positively adjusting the gapbetween adjacent surfaces of a plurality of filter elements during theoperation of the filter, and for inserting cleaning members between theadjacent filter elements and effecting relative rotation between saidcleaning members and said filter elements in order positively to removethe foreign matter accumulating between said gaps, without dismantlingthe filter.

According to one form of the invention a filter is provided wherein thefilter elements constituting the filtering member are formed as ahelical member of impermeable material and of substantially square crosssection, the gaps between the adjacent convolutions of said helicalmember which constitute the filter elements being adapted to bepositively adjusted by the application of axial pressure or tensionthereto.

According to another form of the invention a filter is provided whereinthe filter elements constituting the filtering member are formed as aseries of fiat annular plates of impermeable material mounted upon aperforate hollow drainage tube, the gap between adjacent filter elementsbeing adjustable by means of wedge members which are adapted to bepositively and adjustably located, at a varying distance measuredradially from the central axis of said drainage tube, in wedge-shapedopenings formed at the periphery of adjacent filter elements.

In either of the two forms of the invention referred to above means areprovided for inserting in the gaps between adjacent filtering elements aplurality of cleaning elements or fingers and for efiecting relativerotation between said filter elements and said fingers to effectpositive removal of foreign matter which has accumulated between saidelements during the operation of filtration.

Reference will now be made to the accompanying drawings which illustratedifierent forms of construction according to the invention and in which:

Fig. 1 is a sectional elevation through one form of construction of thefilter according to the invention,

Fig. 2 is a plan of Fig. l with the cover plate removed,

Fig. 3 is a sectional elevation on the line IIIII[ of Fig. 2,

Fig. 4 is a section on the line IVIV of Fig. -3

Fig. '5 is a detail plan view of the cam mechanism for actuating thecleaning fingers of the filter,

Fig. 6 is a section on the line 'VI-VI of Fig. 7

and

Fig. .7 is a detailed elevation of the control members of the filter,

Fig. 8 is a sectional elevation of a second :iorm of construction of afilter according to the invention on the line VIIIVIII of Fig. 9,

Fig. 9 is a plan of the filter shown in Fig, 8,

Fig. 10 is a section on the line X-X of Fig. 8,

Fig. 11 is a section on the line Xl-Xl of Fig. 8,

Fig. 12 is a part section on. the line XlL-XII of Fig. 10.

In the form of construction according to Figs. 1-7 the filter elementsare formed by the convolutions of a helical filtering member I which maybe of metal or other suitable material. The filtering member I mayeither be formed from a solid tube or from a helically wound length ofwire. In the former case the tube from which the helical filteringmember is cut (for example, a steel tube, or a tube of centrifugallycast iron the internal diameter of which is accurately bored out toreceive a drainage tube), is filled with a material, e. g. a metal,capable of receiving the end of a cutting tool and of being re-- movedas a core after the cutting operation. Thus the steel or cast iron tubeis filled with a metal having a lower, preferably a much lower, meltingpoint than the tube from which the helical filtering member is formed.This arrangement enables the helical convolutions of the tube to be cutwith a'thin parting tool set at a suitable angle to give the requiredhelical thread cut, the tool being gradually inset until the core ispenetrated and the steel or cast iron tube being left with a precisionmachined helical thread cut, whilst the inner surface of theconvolutions is without burrs or other irregularities.

The tube from which the helical filtering member is cut mayalternatively be filled with a core of wood which is driven the woodencore being pushed out after the cutting operation. As a furtheralternative the core may be made of a material soluble in chemicalsolutions inert to the material of the helical member, such as syntheticresins which are soluble in alkali.

When the filtering member is formed by the second of the two mentionedmethods, namely from a helically wound length of wire, the wire is madeof bucket section so as to provide parallel surfaces between adjacentconvolutions whenwound into a helix.

The helical member I formed by either of the methods described abovewill provide between adjacent convolutions a gap, the normal size ofwhich is determined by that of the cut made by the cutting tool or thespacing of the convolutions during the winding of the wire. The gapbetween adjacent convolutions is bounded by plane surfaces and providesa passage for filtration which is uniform, within fine limits,throughout the length of the filtering member. The passage forfiltration may be adjusted by applying axial compression or tension tothe helical filtering member I, the convolutions being brought uniformlycloser together or further apart from each other through the resilienceof the material of which the filtering member is made.

In the form of construction according to Figs. 1-7 the filtering memberI is mounted in a cylindrical body 2 closed at the base by a base plate3 and at the top by a flange plate 4, a gear casing 5 and a cover plate6. The cylindrical body 2 is welded or brazed at top and bottom to theflange plate 4 and the base plate 3 respectively; the flange plate issecured to the gear casing 5 by bolts I; and the cover plate 6 is boltedon to the gear casing 5 by bolts 8.

In order to prevent bowing of the filtering member I under axialcompression one or more support members 2a secured to the body 2 arearranged (as shown in Fig. 4'.) to engage about a portion of theperiphery of the filtering member I at one or more points along thelength thereof, the supports leaving sufficient clearance for theintroduction of the cleaning fingers 35.

The gear casing 5 is provided with an inlet port 9 and an outlet portII], the former communicating with the interior of the body 2 and thelatter with the interior of the filtering member I, as will be describedhereinafter.

In order that pressure may be applied in a truly axial direction to thefiltering member I the latter is mounted at its lower end in a solidlower abutment II and at its upper end in an upper abutment I2, thelatter being formed hollow and constituting a drainage tube. The upperportion of the lower abutment II is formed with a shoulder of the sameexternal diameter as the filtering member I and is cut with a helicalgroove Ila similar to that in member I, whilst the end face of theabutment I I and that of the filtering member I are machined fiat, thetail of the lowest convolution of the member I being anchored in arecess I'Ib formed in the upper face of the lower abutment H. Theabutment II also has an integral boss Me which fits within the lower endof the member I.

The lower end of the abutment I I is journalled within a bearing I3secured in the base plate 3 and abuts with a stud I 4, mounted in theend of the abutment II, against a steel ball I5 carried in an adjustablethreaded stop I6 which screws into an internally threaded portion of thebearing I3, as shown in Fig. 1. The lower face of the stop I6 is slottedto receive a screwdriver and is secured in its adjusted position bymeans of a hollow locking screw H. The hearing I3 is sealed externallyby a threaded plug I8.

The upper abutment I2 is hollow but has an external helical groove I2aand is fitted within the upper end of the filter-ing member I in thesame manner as the lower abutment I l.

Ihe upper portion of the abutment I2 is slidably mounted a sleeve I9having gear teeth 20 formed integral therewith the two parts be- 5. ingsecured against rotation by a key. 2| slidable in a key-way 22. Thesleeve I9 is journalled in a bearing formed in a dependent boss 5aintegral with the gear casing 5. A locking ring I9a abutting the lowerface of the boss 5a is secured to the lower end of the sleeve I9 toprevent upward movement thereof within the boss 5a. The upper end of theabutment I2 has secured thereto abridge piece 23 in which is carried anabutment stud 24 which abuts a steel ball 25 carried in the lower end ofa threaded shaft 26 which screws into an internally threaded boss 21integral with the cover plate 6.

The upper end of the boss 21 is sealed with a packing gland 28, 29, 30.Secured on the upper end of the shaft 26 is a barrel 3|.

' In order to provide an audible indication of the completion of acomplete revolution of the barrel 3| the latter carries a spring arm 32the free end of which urges a ball 33 into engagement with the exteriorof the boss 21, the latter having two diametrically opposed longitudinalnarrow slots into which the ball 33 will click at each half revolutionof the barrel.

Also mounted within the body 2 are cleaning fingers 35 (Fig. 3), thelatter being arranged on a D section shaft 36 with interposed spacingcollars 31. The fingers 35 are held securedon the shaft 38 by means ofan upper collar 38 pinned to the shaft 36 by a pin 39, and a nut 49screwed on to a threaded portion of the lower end of shaft 35. The nut40 has a sleeve 4I secured thereto, a grub-screw 34 which also looks thenut 49 on shaft 36.

The sleeve 4I surrounds the upper portion of the bearing 42, in order toprevent foreign matter entering between bearing 42' and shaft 36.

The lower end of the shaft 36 is journalled in a bottom bearing 42secured in the base plate 3, the end of the shaft 36 having screwedthereon an abutment stud 43 which abuts a steel ball 44 carried in anadjustable stop 45 threaded into the lower part of the bearing 42 andlockedv by a hollow screw 46, the arrangement being sim-' ilar to thatfor the bottom bearing I3 for the filtering member I describedpreviously. The bearing 42 is similarly sealed with a threaded plug 41.

The upper end of the shaft 36 is slidably mounted within a bore in thelower end of a pivot member 43 which is rotatably mounted in a bearingformed in the gear casing 5, said pivot member 48 being formed with anexternal shoulder 48a the upper surface of which abuts the under side ofthe gear casing 5 and the lower surface of which forms a seating for oneend of a helical compression spring 50, the other end of which is seatedon a shoulder 380. formed on the collar 38. The lower part of the pivotmember 43 is axially slotted as at 51 and the upper end of the shaft 36is secured against rotation in the pivot member 48 by means of a pin 52transfixing the pin and slot 5I.

Secured on the upper end of the pivot member 48 by a pin 53 is a camfollower 54 on which Mounted in an opening formed in the gear casing 5is a pivot pin 51 (Fig. 1) secured by a nut 58 on the lower threaded endthereof. The middle portion of the pin 51 is of increased diameter andhas rotatably mounted thereon a spur wheel 59, meshing with the gearedsleeve l9, and a cam disc 60, the spur wheel 59 and cam disc 60 beingriveted together and the cam disc 69 carrying a drivingpin 6| whichextends upwards therefrom. The spur wheel 59 is engaged by a ratchetpawl 62 pivotally mounted on a pin 63 secured in the gear casing 5 andcarrying a spring 64 one end of which abuts the wall of the gear casing5 and the other end of which abuts ,a pin 65 carried by the pawl 62, thespring 64 urging the pawl into engagement with the teeth of the spurwheel59.

Pivotally mounted in the cover plate 8 is an operating shaft 66 for thecam disc 60, the lower end of the shaft 66 being of enlarged diameterand having a slot 61 thereon to engage the driving pin 6|. The openingin the cover plate 6 through which the shaft 66 extends is sealed by apacking gland 68, 69, 19. The end of the shaft 66 extending upwardlythrough the gland 68, 69, III, has a knurled head II secured thereon bya screw '12, the head II having an arcuate portion 13 of a radiusslightly greater than the barrel 3| cut away from its periphery (Figs. 6and 7). The barrel 3I is also formed with an arcuate recess 14, of aradius slightly greater than that of the knurled. head TI and of a depthslightly greater than that of the head 'II, the purpose of which will beexplained hereafter.

The cleaning fingers 35 must have. sufiicient strength to resistbuckling when'engaging between the convolutions of the filter member Iand for this purpose they are made of a thickness such that they will becapable of insertion between the convolutions when they are at theirmaximum spacing from each other or nearly so. It will be appreciated,therefore, that in the example of construction illustrated the helicalfiltering member I is cut to give a space between the convolutions whichis slightly greater than the thickness of the cleaning fingers 35, the

filter element I being under slight axial com dmpression when the spacesbetween the convolutions just admit'the cleaning fingers 35.

Adjustment of the gap for filtration is efiected by rotation of thebarrel 3| the latter being conveniently provided with an indication markand ithe boss 21 being preferably calibrated, as shown in Fig. 7.

lhe operation of cleaning the filtering member I is efiected by rotationof the latter when the cleaning fingers are engaged between theiconvolutions of the filtering member I, and for this purpose it isnecessary to ensure that the cleaning fingers cannot be damaged by anattempt to tighten up the convolutions when'the fingers are engagedtherebetween, or by rotation of the filtering member I when the gapbetween the convolutions is not such as to admit the cleaning fingers.It is for this purpose that the barrel 3| is formed with an arcuaterecess F4, as described above, the depth of which measured axially ofthe barrel is sufficient to accommodate the thickness of the knurledhead H, the recess I4 being located at a point along the barrel suchthat when the spacing between the 1 convolutions is that required forcleaning operation the recess 14 lies in the same horizontal plane asthe knurled head ll. It will be seen that in any other position ofadjustment of the barrel 3I the knurled head 'iI is prevented fromrotation through the engagement of the periph- 7'. cry of the barrels!in the arcuate recess 1-3 .in the knurled .head 'Il.

The position of the cleaning fingers 35, the cam 60 and the cam follower54 immediately prior to the cleaning operation is shown in Fig. 5. Theknurled head II is also in the same horizontal plane as the recess I4,and the recesses 14 and 73 are directly opposite each other (Fig. 6). Inthis position the cleaning fingers 35 are disengaged from the filteringmember I, the cam follower 54 being engaged by the cam edge on the camdisc 60 and the pivot member 48 having been partially rotated againstthe action of spring 55 and thereby having rotated to a correspondingdegree the shaft 36 which is engaged in the slotted lower end of thepivot member 48.

If the knurled head (I is now rotated in a clockwise direction thedriving pin BI of the cam disc 60 engaging in the slot 51 of theoperating shaft 66 imparts rotation in a clockwise direction to the camdisc 60 and also to the spur wheel 59 which is secured thereto and inmesh with the gear sleeve I9. The first small rotation of the cam disc60 causes disengagement of the cam follower 54 from the cam edge andthereby permits rotation of the pivot member 48 in a clockwise directionunder the action of spring 55, such movement of the pivot member alsoimparting corresponding rotation to the shaft 36 carrying the cleaningfingers 35 which are thereby brought into engagement between theconvolutions of the helical filtering member I. It will be understoodthat the positioning of the cleaning fingers 35 axially of the shaft 36is such that in the relative positions of the parts above referred tothe cleaning fingers are accurately positioned with respect to theconvolutions of the filtering member I so as to engage positivelytherebetween. In order to facilitate the entry of the device of thecleaning fingers 35 between the convolutions in this position of thefiltering member I the edges of the convolutions are slightly cut awayover a small portion of their periphery so to provide a point of entrywhich is of V-section. Upon further rotation of the knurled head 'II thefiltering member I will also rotate therewith, being keyed to the gearedsleeve I9 which meshes with the spur wheel 59, and during this operationthe cleaning fingers engaged between the convolutions will positivelyremove foreign matter which has accumulated therebetween during theoperation of filtering. After the completion of one revolution of theknurled head II and, accordingly, of the cam disc 68 and the filteringmember I, the cam edge on the cam disc 60 will again engage the camfollower 54 and cause it to pivot in an anticlockwise direction thismovement being accordingly transmitted to the shaft 36 carrying thecleaning fingers 35 and the latter thereby being withdrawn from betweenthe convolutions of the filtering member I'.

It will be obvious that during the previous operation in which thefiltering member I was rotated with the cleaning fingers engaged in theconvolutions thereof the blades will have been caused to move axially byan amount dependent on the pitch of the helix and such movement isaccommodated by the spring 50, the upper end of the shaft 36 slidingupwardly within the slotted lower end of the pivoted member 48. As soonas the cleaning fingers 35 are disengaged from the filtering member Ithey will be returned to their normal position by the spring 50.

It will be noted that the sleeve M will ef-' fectively prevent foreignmatter dislodged by the cleaning fingers from entering between the shaft36 and the. lower bearing -42 whatever the axial position of the shaft36.

After the conclusion of the cleaning operation described above, when thearcuate recesses in the barrel 3i and the knurled head H are once morein the relative position shown in Fig. 6, the barrel 3I may be rotatedto give the desired gap between the convolutions of the filter member Iin accordance with the requirements for filtration at any time, and suchadjustment may be made if desired during the operation of the filter.The foreign "matter removed by the cleaning fingers 35 will accumulateat the bottom of the body 2 and may be removed :by drainage .from thebase of the body, a removable drainage :plug 15 being convenientlyprovided for this purpose-as shown in Fig. 1.

As shown in Figs. '6 and '7 the shaft 66 and head H :are transfixed by apin Ha which is slidably mounted and formed at one end with an obliqueface 'Hb. Mounted in the cover plate 6 is an abutment post 5a. It willbe seen that when the knurled head H is rotated and the face I lb of pin1 la abuts the post 6a the pin will be moved axially so that uponfurther rotation of the head 'H the plain end of the pin will abut thepost Ba and prevent further rotation of said head III until the pin Hais axially displaced by the operator. In this way the rotation of thehead II through one complete revolution when carrying out the cleaningof the filter members is automatically indicated to the operator whenthe plain end of the pin -IIa abuts the post 611, and in this positionthe head II and barrel 3| are correctly positioned to allow subsequentreadjustment of the filtering member I. As shown, the axial movement ofpin '1 la is preferably limited by a resiliently urged transverse pin 1lo engaging in a recess in the body of the pin I Ia.

The liquid to be filtered is delivered through the port 9 whichcommunicates with the interior of the body 2 and after passing betweenthe convolutions of the filtering member I travels upwardly within thefilter member I and leaves It will be seen that the provision of theratchet pawl 52 engaging the spur wheel 59 prevents damage to thecleaning fingers 35 which would be caused if the filter member I' wereto be rotated 'inan anticlockwise direction, the arrangement illustratedproviding for movement of the cleaning fingers in an upward directiononly. It will also :be noted that it is not possible to effectadjustment of the spacing of the convolutions of the filtering member :Iwhilst the cleaning fingers 35 are engaged therebetween since theperiphery of the knurled head engages within the arouate recess I4during any position except that in which the cleaning fingers aredisengaged fro the filter member I.

In the second form of the construction of the invention illustrated inFigs. 8-12 the filter member, instead of being formed as a helicalmember, consists of a plurality of plates arrangedon a drainage tube,means being provided for positively adjusting the interval between theplates to vary the degree of filtration within the limits required.

In this form of construction the filter is formed of a tubular body .80on the lower end of which iszseoureda base plate 8| and on the upper endof which is secured a cover plate 82. The base plate 8| has a centraloutlet port 83'formed thereplurality of openings 86 which as shown areequispaced about the periphery of the said drainage tube 05. The saiddrainage tube 85 is also formed with three equispaced longitudinalgrooves 81 (Fig. 11) the purpose of which will be apparent hereinafter.The lower end of the drainage tube 85 is journalled in a bearing formedin the base plate i whilst the upper end is integral with a solidportion 88 on which is formed a peripheral flange 89 which is housed inacorresponding recess 90 formed in the underside of the cover plate 32.The upper end of the solid portion 88 of the drainage tube extendsthrough a packing gland 9! mounted in a central boss 82a integral withthe cover plate 82 and has secured at its end a knurled head 92. theunderside of the cover plate 02 by means of screws 93 is a ring 0 3 theupper surface of which abuts the lower face of the fiange 89 and retainsit in position within the recess 90. The ring 94 has a clearance about asleeve mounted on the upper solid portion of the drainage tube 85.

grooves 81, whereby said plate 92 is secured against rotation relativeto the drainage tube 85. Mounted below said abutment ring 91 is aplurality of filter plates 98 which may be of metal, glass, syntheticresin or other impermeable material, each of said filter plates 98 beingprovided with inwardly directed equispaoed radial tongues 08a adapted toengage in groove 01 and thus be axially movable but secured againstrotation on the drainage tube 85. The peripheral edge of each of saidfilter plates 98 is of inverted V-section. The lowermost of said filterplates 98 is engaged by a further abutment ring 99 the lower face ofwhich is formed with a peripheral shoulder forming a seating for one endof a spring I00 the other end of which seats on a corresponding shoulderformed in the upper surface of a further abutment ring IOI which isaxially located on the drainage tube 85 by means of a ring I02 locatedin an annular groove in the lower end of the drainage tube 85. I

Equispaced' about the assembly of filter plates and drainage tube arethree pillars I03 which are journalled at their upper and lower ends inbores formed in the cover plate 02 and the base plate 8| respectively.

Mounted on a shoulder formed on the upper portion of each of the pillarsI03 is a pivoted member I04 the upper portion of the shaftbeing machinedsquare and the pivoted members I04 being formed with correspondingsquare openings so as to secure them against rotation on said pillarsI03. Each of said pivot members I04 is formed with a cam recess I04a,each of which latter is arranged-to engage about one of three equispacedpins I05 which are arranged on the underside of the ring 90. The ring 90is provided over a portion of its periphery with teeth I06 which meshwith a spur wheel I0'I mounted on the lower end of a shaft I03journalled in an opening sealed by a packing gland I09, formed Securedto I 10 in the cover plate 82. A knurled head H0 is pinned to the upperend of the shaft I08.

Each of the pillars I03 has a longitudinal groove III formed therein inwhich are located a plurality of steel balls H2, the depth of thegrooves III being such that a portion of each of the balls I I2 extendsradially beyond the circumference of the shaft I03. The projectingportions of the balls I I2 engage within the annular grooves ofV-section which are formed between the peripheries of adjacent filterplates 98.

Also mounted within the body 80 is a shaft I I4 the lower end of which(not shown) is journalled within the base plate 8| and the upper end ofwhich is journalled within the cover plate 82 .and sealed therein in apacking gland H5. The

portion of the shaft H4 within the casing 00 is formed of D-section andhas mounted thereon to the section of the shaft I I4, whereby they arelocked against rotary movement on said shaft. Said fingers H6 andcollars H'I are also secured against axial movement bysuitable means(not shown on the drawing). Secured on the upper end of the shaft H4 isa knurled head I 50. The latter has an arcuate portion out way from itsperiphery and the knurled head H0 also has a similar portion cut awayfrom its periphery the arrangement being such that, as shown in Fig. 9,the knurled head H8 whereby the shaft Hi'carrying the cleaning fingers IIt may be rotated, cannot be rotated until the two arcuate recessesonthe knurled heads H8 and H0 lie directly opposite each other. ,Theposition of the knurled head H8 in Fig. 9 is that in which the cleaningfingers H6 are not engaged between the plates 98 and it will be seenthat in order to effect rotation of theshaft H land the fingers H6 theknurled head I I0 must first be brought into a definite angularposition. Any movement of the knurled head I I0 will rotate the shaftI08 and the spur wheel I01 carried thereon, the latter meshing with thetoothed portion 06 of the annular plate 90, which is thereby partiallyrotated about itsaxis. Such movement will cause the pins I05 to engagethe cam recesses I04a of the pivot members I04 and thus effectpartialrotation of the pillars I03 in one direction or the other. Itwill be clear from a considerationof Fig. 11 that rotation of the,pillars I03 will cause the balls H2 to penetrate to a varying degreewithin theV-section groove at the periphery of the plates 98 and, in so.doing, vary the space between adjacent plates 98 from zero to, forexample,.8 thousandths of-an inch, the maximum gap between the plates 90being provided when the balls H2 and the axes of the plates 98 and thepillarsI03 lie in a straight line. The increased axial length of theassemblyof plates 'on the drainage tube is accommodated by thecompression of the spring I00 the latter returning the plates to theirclosed condition upon reversing the rotation of the pillars I03. v

It will be seen therefore that the knurled head I I0 may be so locatedon the shaft I08 that when the recesses in the knurled heads H8 and H0lie directly opposite each other the space between the plates98 willcorrespond to the thickness of the cleaning fingers I I6, and that inthis position of the knurled head H0 the knurled head H8 can be rotatedto move the cleaning fingers H6 into engagement between the plates 98.The

2, e42, me

degree of movement of the cleaning fingers HE is shown in Fig. tonormal, disengaged, position of the fingers being shown in full lines,and the cleaning position being shown in chaindotted lines. When thecleaning fingers are in the latter position the knurled head 92 may bemanually rotated in order to rotate the filter plates 98 secured thereonand thereby efiect by the relative movement between the plates and thecleaning fingers the removal of foreign matter which has accumulatedbetween said plates. After one or more rotations of the plates thecleaning fingers are restored to their normal disengaged position by areverse rotation of the knurled head I I8 and the gap between the platesmay thereafter be adjusted as required by rotation of the knurled headH0.

It will be seen that the arrangement described provides a means wherebythe gap between adjacent filter plates may be regulated as required andif necessary during operation of filtering, and that, when filtration isimpeded by an accumulation of foreign matter between the plates thelatter may be readily cleaned, whilst momentarily discontinuingoperation of the filter, by actuation of the cleaning fingers androtation of the plates. The removed foreign matter may be drained out ofthe filter by removing a drainage plug H9 (Fig. 8) from the base plate8|.

We claim:

1. A filter comprising a plurality of rotatably mounted filter elementsforming gaps between them for passage of a liquid to be filtered andconstituting a filtering member, means for relatively adjusting saidelements axially to reduce the gaps between them for filtration and forrelatively opening the gaps for cleaning of the filter elements, aplurality of cleaning members mounted rotatably for insertion intorespective gaps between the filter elements, and means controlled bysaid adjusting means for relatively rotating the filter elements andcleaning members only while the filter elements are relatively adjustedaxially to open the gaps to remove foreign matter accumulating in. saidgaps during filtration.

2. A filter as defined in claim 1, including inter-controlling membersconnected respectively to said means for relatively adjusting the filterelements and said means for relatively rotating said filter elements andcleaning members and cooperative to prevent relative rotation betweenthe cleaning members and filter elements while said adjusting means forthe filter elements is operable and to prevent operation of saidadjusting means while the cleaning members are inserted into the gapsbetween the filter elements.

3. A filter as defined in claim 1, wherein said filtering member is ahelical member having'gaps between adjacent convolutions constitutingthe filter elements, the filter elements having parallel adjacentsurfaces, and wherein'said adjusting means is operable to vary thespaces or gaps between said surfaces by the application of axialcompression or tension to said helical member;

4. A filter as defined in claim 3, including a filter body in which saidhelical member is mounted, the filter body being provided with saidmeans for applying axial compression and tension to said helical memberand for providing a predetermined spacing between the convolutionsforming said filter elements for inser- 12 tion of said cleaning membersbetween the convolutions of said helical member, and means for rotatingsaid helical member while said cleaning members are interengaged withthe convolutions of said helical member.

5. A filter comprising a filter body, a helical filtering member mountedrotatably therein, means for applying axial compression and tension tothe filtering member to vary the spacing between the convolutionsthereof, a shaft mounted rotatably in the filter body and havingcleaning fingers equidistantly spaced axially thereon and rotatable intoand out of the spaces between convolutions of the filtering member, amanual control device operable exteriorly of the filter body andconnected to said shaft and operable by movement in one direction torotate the cleaning fingers into the spaces between the convolutions ofthe filtering member while said convolutions are spaced apart apredetermined distan-ce, means operable by further movement of saidcontrol device for rotating the filtering member, means operable by acontinued movement of said control device in said direction to disengagethe cleaning fingers from the filtering member, and means operable by afinal movement of said control device in said direction for locking thefiltering member from rotation.

6. A filter comprising a filter body, a helical filtering member mountedrotatably therein, means for applying axial compression or tension tothe filtering member to vary the spacing between the convolutionsthereof, a shaft mounted rotatably in said body and carrying cleaningfingers movable into and out of the spaces between the convolutions ofthe filtering member, an operating member, a cam connected to saidoperating member for rotation thereby, gearing connected to said cam andhaving a spline connection with the filtering member, and a cam followerconnected to the shaft carrying the cleaning fingers and operative byrotation of said operating member to disengage the cleaning fingers fromthe spaces between the convolutions of the filtering member.

7. A filter as defined in claim 6, wherein said means for applying axialcompression or tension to the helical filtering member includes a shaftthreaded in said filter body and abutting against said filtering memberand a head fixed to said threaded shaft, and said head and operatingmember having portions which are interengageable to lock said operatingmember from operation while the spacing between the convolutions of thefiltering member is insufiicient to admit the cleaning fingers.

8. A filter as defined in claim 6, wherein said means for applying axialcompression or tension to the helical filtering member includes a shaftthreaded in said filter body and abutting against said filtering memberand a head fixed to said threaded shaft, and said head and op cratingmember having portions which are interengageable to lock said head fromoperation while the cleaning fingers are in the spaces between theconvolutions of the filtering member.

9. A filter as defined in claim 6', wherein said cleaning fingers aresplined on said shaft which carries them for movement axially thereon inconformity with the paths of movement of the spaces between theconvolutions of the filtering member during rotation of said member, andincluding a spring acting on said cleaning fingers to permit axialmovement thereof during rotation of the filtering member and to restorethe inwardly or outwardly between the bevelled edges of adjacent filterplates to vary the gaps between them, cleaning elements mountedrotatably in the filter body for movement into and. out of the gapsbetween the filter plates, and means for relatively rotating the filterplates and cleaning elements.

11. A filter as defined in claim 10, wherein said wedge means comprisesa plurality of pillars mounted rotatably in said filter body parallel toand about the axis of saidfiltering member and having axial groovestherein, balls mounted in the grooves in the pillars, and means forpartially rotating the pillars simultaneously to force the balls in therespective grooves thereof between the bevelled peripheral edges of saidplates to vary the gap between adjacent plates.

12. A filter as defined in claim 10, including a shaft mounted rotatablyin the filter body in parallelism with the axis of the assembly offilter plates and having said cleaning elements fixed thereon at regularintervals axially thereof, and

' means for rotating said shaft to engage the cleaning elements betweenthe filter plates.

13. A filter as defined in claim 10, includin an operating headconnected to said cleaning ele I ments for rotating them, and a, headconnected to said wedge means forvarying the gaps between said filterplates, said heads having portions which are interengageable to lock oneof said heads from operation except while the other head occupies apredetermined position.

14. A filter as defined in claim 10, including an operating headconnected to said cleaning elements for rotating them, and a headconnected to said wedge means for varying the gaps between said filterplates, said heads having portions which are interengageable to lock theclean- I ing elements from rotation except while said wedge means is incondition to provide a predetermined spacing between the filter plates.

15. A filter as defined in claim 10, including an' operating headconnected to said cleaning elements for rotating them, and a headconnected to said Wedge means for varying the gaps between said filterplates, said heads having portions which are interengageable to preventoperation of said wedge means while the cleaning elements are betweenthe filter plates.

16. A filter as defined in claim 10, wherein said wedge means comprisesa plurality of axially grooved pillars mounted rotatably in th filterbody in parallelism with and spaced about the axis of said filteringmember and balls mounted in the grooves of the pillars adjacent to thebevelled peripheralv edges of the filter plates, a ring mountedrotatably in the filter body and having means for rotating it, camsfixed to the pillars, and pins on said ring and cooperative with samecams for partially rotating the pillars by rotation of said ring. I

CHARLES SAMUEL GARLAND. FRANCIS HERON ROGERS.

References Cited in the me of this patent UNITED STATES PATENTS

